1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
4 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
5 */
6
7#include <linux/sched.h>
8#include <linux/slab.h>
9#include <linux/spinlock.h>
10#include <linux/completion.h>
11#include <linux/buffer_head.h>
12#include <linux/xattr.h>
13#include <linux/posix_acl.h>
14#include <linux/posix_acl_xattr.h>
15#include <linux/gfs2_ondisk.h>
16
17#include "gfs2.h"
18#include "incore.h"
19#include "acl.h"
20#include "xattr.h"
21#include "glock.h"
22#include "inode.h"
23#include "meta_io.h"
24#include "quota.h"
25#include "rgrp.h"
26#include "trans.h"
27#include "util.h"
28
29static const char *gfs2_acl_name(int type)
30{
31	switch (type) {
32	case ACL_TYPE_ACCESS:
33		return XATTR_POSIX_ACL_ACCESS;
34	case ACL_TYPE_DEFAULT:
35		return XATTR_POSIX_ACL_DEFAULT;
36	}
37	return NULL;
38}
39
40static struct posix_acl *__gfs2_get_acl(struct inode *inode, int type)
41{
42	struct gfs2_inode *ip = GFS2_I(inode);
43	struct posix_acl *acl;
44	const char *name;
45	char *data;
46	int len;
47
48	if (!ip->i_eattr)
49		return NULL;
50
51	name = gfs2_acl_name(type);
52	len = gfs2_xattr_acl_get(ip, name, &data);
53	if (len <= 0)
54		return ERR_PTR(len);
55	acl = posix_acl_from_xattr(&init_user_ns, data, len);
56	kfree(data);
57	return acl;
58}
59
60struct posix_acl *gfs2_get_acl(struct inode *inode, int type, bool rcu)
61{
62	struct gfs2_inode *ip = GFS2_I(inode);
63	struct gfs2_holder gh;
64	bool need_unlock = false;
65	struct posix_acl *acl;
66
67	if (rcu)
68		return ERR_PTR(-ECHILD);
69
70	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
71		int ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
72					     LM_FLAG_ANY, &gh);
73		if (ret)
74			return ERR_PTR(ret);
75		need_unlock = true;
76	}
77	acl = __gfs2_get_acl(inode, type);
78	if (need_unlock)
79		gfs2_glock_dq_uninit(&gh);
80	return acl;
81}
82
83int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
84{
85	int error;
86	size_t len;
87	char *data;
88	const char *name = gfs2_acl_name(type);
89
90	if (acl) {
91		len = posix_acl_xattr_size(acl->a_count);
92		data = kmalloc(len, GFP_NOFS);
93		if (data == NULL)
94			return -ENOMEM;
95		error = posix_acl_to_xattr(&init_user_ns, acl, data, len);
96		if (error < 0)
97			goto out;
98	} else {
99		data = NULL;
100		len = 0;
101	}
102
103	error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
104	if (error)
105		goto out;
106	set_cached_acl(inode, type, acl);
107out:
108	kfree(data);
109	return error;
110}
111
112int gfs2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
113		 struct posix_acl *acl, int type)
114{
115	struct inode *inode = d_inode(dentry);
116	struct gfs2_inode *ip = GFS2_I(inode);
117	struct gfs2_holder gh;
118	bool need_unlock = false;
119	int ret;
120	umode_t mode;
121
122	if (acl && acl->a_count > GFS2_ACL_MAX_ENTRIES(GFS2_SB(inode)))
123		return -E2BIG;
124
125	ret = gfs2_qa_get(ip);
126	if (ret)
127		return ret;
128
129	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
130		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
131		if (ret)
132			goto out;
133		need_unlock = true;
134	}
135
136	mode = inode->i_mode;
137	if (type == ACL_TYPE_ACCESS && acl) {
138		ret = posix_acl_update_mode(&nop_mnt_idmap, inode, &mode, &acl);
139		if (ret)
140			goto unlock;
141	}
142
143	ret = __gfs2_set_acl(inode, acl, type);
144	if (!ret && mode != inode->i_mode) {
145		inode_set_ctime_current(inode);
146		inode->i_mode = mode;
147		mark_inode_dirty(inode);
148	}
149unlock:
150	if (need_unlock)
151		gfs2_glock_dq_uninit(&gh);
152out:
153	gfs2_qa_put(ip);
154	return ret;
155}
156